Chandrayaan 2 breezes through fourth orbit-lowering manoeuvre before separation

tech2 News StaffAug 30, 2019 19:03:22 IST

Chandrayaan 2, India's second mission to the moon, has successfully compeleted its fourth orbit-lowering manoeuvre around the moon. ISRO confirmed that the lunar-bound manoeuvre, which was planned for 6-7 am on 30 August, was completed at 6.18 pm IST using the spacecraft's onboard propulsion system.

The manoeuvre has moved Chandrayaan 2 from its current 179 x 1411 km (nearest x farthest distance) elliptical orbit to a near-circular orbit of 124 x 164 km and the duration of the manoeuvre was 1155 seconds (19.25 minutes). The next Lunar bound orbit manoeuvre is scheduled on September 01, 2019 between 6.00 pm - 7.00 pm IST.

The Chandrayaan 2 composite has carried out a total of four successful in-orbit manoeuvres since it entered lunar orbit — all in an attempt to lower its altitude in preparation for landing. The fourth manoeuvre today has placed the spacecraft on a circular path that passes over the lunar poles at a distance of about 100 km from the surface.

Entering this circular orbit is the mission's fourth milestone before the Vikram lander separates from the orbiter to make its planned soft-landing on the moon's surface on 7 September.

Chandrayaan 2 composite orbiting the moon before the lander's separation. Image: ISRO

The 124 x 164 km circular orbit that Chandrayaan 2 is in is close enough for the Vikram lander, currently bound to the orbiter in a 'composite', to separate and attempt a landing. Separation and landing sequences are planned for 2 September and 7 September at 1.40 am, respectively. Between these two important days, the first maps of the landing site will be created (on 3 and 4 September) to ensure the landing site is as safe as previously thought to make a soft-landing. This is a crucial step in the mission since ISRO's mission engineers won't be operating the spacecraft remotely.

The orbiter will also be surveilling its year-long home for the first time, ensuring that no damage was caused to its instruments on the journey thus far, and conducting a thorough examination of the Vikram lander's landing site at the moon's South Polar region. Chandrayaan 2 is expected to begin its long-awaited powered descent and landing on 7 September at 1.40 am IST in a landing sequence that the ISRO Chief describes as '15 minutes of terror'.

While subsequent events in the mission won't be streamed live, you can catch live updates on the mission on our dedicated Chandrayaan 2 domain, our Twitter page, ISRO's website, or Twitter page.